+/*
+ * $XConsortium: Unwrap.c,v 1.9 94/04/17 20:16:43 keith Exp $
+ *
+ *
+Copyright (c) 1989 X Consortium
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of the X Consortium shall not be
+used in advertising or otherwise to promote the sale, use or other dealings
+in this Software without prior written authorization from the X Consortium.
+ * *
+ * Author: Keith Packard, MIT X Consortium
+ */
+
+#include <X11/Xos.h>
+#include <X11/X.h>
+#include <X11/Xmd.h>
+#include <X11/Xdmcp.h>
+
+#ifdef HASXDMAUTH
+
+/*
+ * The following function exists only to demonstrate the
+ * desired functional interface for this routine. You will
+ * need to add the appropriate algorithm if you wish to
+ * use XDM-AUTHENTICATION-1/XDM-AUTHORIZATION-1.
+ *
+ * The interface for this routine is quite simple. All three
+ * arguments are arrays of 8 unsigned characters, the first two
+ * are 64 bits of useful data, the last is 56 bits of useful
+ * data packed into 8 bytes, using the low 7 bits of each
+ * byte, filling the high bit with odd parity.
+ *
+ * Examine the XDMCP specification for the correct algorithm
+ */
+
+#include "Wrap.h"
+
+void
+XdmcpUnwrap (input, wrapper, output, bytes)
+ unsigned char *input, *output;
+ unsigned char *wrapper;
+ int bytes;
+{
+ int i, j, k;
+ unsigned char tmp[8];
+ unsigned char blocks[2][8];
+ unsigned char expand_wrapper[8];
+ auth_wrapper_schedule schedule;
+
+ _XdmcpWrapperToOddParity (wrapper, expand_wrapper);
+ _XdmcpAuthSetup (expand_wrapper, schedule);
+
+ k = 0;
+ for (j = 0; j < bytes; j += 8)
+ {
+ if (bytes - j < 8)
+ return; /* bad input length */
+ for (i = 0; i < 8; i++)
+ blocks[k][i] = input[j + i];
+ _XdmcpAuthDoIt ((unsigned char *) (input + j), (unsigned char *) tmp, schedule, 0);
+ /* block chaining */
+ k = (k == 0) ? 1 : 0;
+ for (i = 0; i < 8; i++)
+ {
+ if (j == 0)
+ output[j + i] = tmp[i];
+ else
+ output[j + i] = tmp[i] ^ blocks[k][i];
+ }
+ }
+}
+
+#endif /* HASXDMAUTH */